The first clock I purchased was already broken before I bought it - the seller forgot to mention it wasn't working. The second clock I bought got broken in the mail because the seller didn't pack it properly.
So to ensure I received an alarm clock that worked properly, I bought two others from two different sellers. I then received both in the mail within a few days of each other - and BOTH worked.
But then this morning about 5.45am, I discovered that I had a secret alarm clock that I hadn't been aware of: I was awakened by the gentle but very insistent licking of my big toe. My dog Genevieve has now discovered the ideal way of waking me up in the morning!